WO2012168324A1 - Biodegradable polyester mixture - Google Patents

Abstract

The invention relates to a biodegradable polyester mixture, containing i) 5 to 90 wt%, relative to the total weight of components i and ii, of at least one polyester based on aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds; ii) 10 to 95 wt%, relative to the total weight of components i and ii, of at least one homopolyester or copolyester selected from the group comprising polylactides (PLAs), polycaprolactones, polyhydroxyalkanoates (e.g., PHB or PHB/V), and polyesters from aliphatic dicarboxylic acids and aliphatic diols; iii) 0.1 to 15 wt%, relative to the total weight of components i and ii, of a) a copolymer that contains epoxy groups and that is based on styrene, acrylic acid ester, and/or methacrylic acid ester, b) a bisphenol A epoxy, or c) a natural oil, fatty acid ester, or fatty acid amide containing epoxy groups; and iv) 0.1 to 5 wt%, relative to the sum of components i and ii, of iv-1) one or more finely divided phyllosilicates, the surface of which is modified with one or more quaternary ammonium salts or phosphonium salts and/or sulfonium salts, and/or iv-2) nanoparticulate silicon dioxide produced by means of flame pyrolysis, the surface of which is hydrophobically modified and which has a number-average diameter of the primary particles of 1 to 20 nm; v) 0 to 30 wt%, relative to the sum of components i and ii, of additives, such as stabilizers, nucleating agents, lubricants, anti-blocking agents, waxes, softening agents, surfactants, antistatic agents, anti-fogging agents, dyes, and inorganic or organic fillers different from component iv. Said biodegradable polyester mixture is suitable for producing foils, films, molded parts, and fibers.

Description

 Biodegradable polyester blend Description

The invention relates to a biodegradable polyester mixture containing mineral fillers, films and films containing the polyester blend, and their use for mulch films in agriculture and as packaging material, in particular for food.

Biodegradable mixtures of i) synthetically produced polyester materials and ii) homo- or copolyesters selected from the group consisting of polylactide, polycaprolactone, polyhydroxyalkanoates and polyesters of aliphatic dicarboxylic acids and aliphatic diols are known (see EP-B 792 309). Such mixtures ideally combine the desirable properties of the individual components, for example the generally good processing and mechanical properties of the synthetic polyesters with the usually more cost-effective availability and ecologically safe production and disposal of the ii) polymers listed above, such as polylactide, polycaprolactone, polyhydroxyalkanoates and polyols. lyester from aliphatic dicarboxylic acids and aliphatic diols.

In practice, however, it is often difficult to achieve the desired property combination. Polylactide and Polyhydroxyalkanoate must be pre-dried consuming to prevent degradation of the polymers. In particular for film applications, the mixtures have too low a bubble stability. This applies in particular to mixtures with more than 20% polylactide or polyhydroxycarboxylic acids and <80% of aromatic-aliphatic copolyester. Furthermore, in particular thin films, which are manufactured from the mixtures of the prior art, have too low tear propagation resistance. This occurs especially with thin films containing larger shares or even predominantly polylactide or polyhydroxycarboxylic acid.

The invention is therefore based on the object, biodegradable mixtures of i) synthetically produced polyester materials and ii) homo- or copolyesters - selected from the group consisting of polylactide, polycaprolactone, polyhydroxyalkanoates and polyesters of aliphatic dicarboxylic acids and aliphatic diols - available provide that do not have the above-mentioned disadvantages.

It has been found that in particular the tear propagation resistance of known materials can be improved from biodegradable polyester mixtures if certain clay minerals in particle form are added to the mixtures. It is known from WO 2006/074815 to add mineral fillers to biodegradable polyester mixtures. In WO 2007/099427 the addition of mineral nanoparticles to such mixtures is described, whereby in particular the heat resistance is to be increased.

A relationship between tear strength and the addition of mineral fillers is not described in any of the documents.

The invention relates to a, preferably biodegradable, polyester mixture containing

From 5 to 90% by weight, based on the total weight of components i and ii, of at least one polyester based on aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds; ii) from 10 to 95% by weight, based on the total weight of components i and ii, of at least one homo- or copolyester selected from the group consisting of polylactides (PLA), polycaprolactones, polyhydroxyalkanoates (eg PHB or PHB / V) and polyesters from aliphatic dicarboxylic acids and aliphatic diols; iii) from 0.1 to 15% by weight, based on the total weight of components i and ii, of a) an epoxide group-containing copolymer based on styrene, acrylate and / or methacrylic acid ester, b) a bisphenol A epoxide or c) an epoxide group-containing natural oil, fatty acid ester or fatty acid amide; and iv) 0.1 to 5% by weight, based on the sum of components i and ii

 iv-1) one or more finely divided layered silicates whose surface is modified with one or more quaternary ammonium salts or phosphonium salts and / or sulfonium salts, and / or

iv-2) nanoparticulate silica produced by flame pyrolysis, whose surface is hydrophobically modified and which has a number-weighted diameter of the primary particles of 1 to 20 nm; v) 0 to 30 wt .-%, based on the sum of components i and ii, additives such as stabilizers, nucleating agents, lubricants and antiblocking agents, waxes, softeners, surfactants, antistatic agents, antifog agents, dyes and of the component iv various inorganic or organic fillers. Furthermore, the invention relates to processes for the preparation of the polyester mixtures according to the invention, the use of the polyester mixtures according to the invention for the production of moldings, films, films or fibers as well as films, films, moldings or fibers containing the polyester mixture according to the invention.

In principle, all polyesters based on aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds, so-called partly aromatic polyesters, come into consideration as component i for the preparation of the biodegradable polyester mixtures according to the invention. Of course, mixtures of several such polyesters are suitable as component i. Partly aromatic polyesters according to the invention are also understood to mean polyester derivatives such as polyether esters, polyester amides or polyetheresteramides. Suitable partially aromatic polyesters include linear non-chain extended polyesters (WO 92/09654). Preferred are chain-extended and / or branched partially aromatic polyesters. The latter are known from the documents cited at the outset, WO 96/15173 to 15176, 21689 to 21692, 25446, 25448 or WO 98/12242, to which reference is expressly made. Mixtures of different partially aromatic polyesters are also possible. In particular, under partly aromatic polyesters products such as Ecoflex ^® (BASF Aktiengesellschaft) and Origo-Bi ^® (Novamont) to understand.

Particularly preferred partially aromatic polyesters include polyesters as essential components

A) an acid component of a1) 30 to 99 mol% of at least one aliphatic or at least one cycloaliphatic dicarboxylic acid or its ester-forming derivatives or mixtures thereof a2) 1 to 70 mol% of at least one aromatic dicarboxylic acid or its ester-forming derivative or mixtures thereof and a3) 0 to 5 mol% of a sulfonate compound, B) a diol component selected from at least one C ₂ to Ci ₂ alkanediol and at least one C ₅ - to C ₀ -Cycloalkandiol or mixtures thereof and, if desired, in addition, one or more components selected from a component selected from c1) at least one dihydroxy compound of the formula I containing ether functions

HO - [(CH ₂ ) _n -O] _m -H (I) in the n for 2, 3 or 4 and m for an integer from 2 to 250 are c2) at least one hydroxybutyrate of the formula IIa or IIb

wobei R¹ eine Einfachbindung, eine (CH₂)_Z-Alkylengruppe, mit z = 2, 3 oder 4, oder eine Phenylengruppe bedeutet c6) mindestens einer Aminocarbonsäure ausgewählt aus der Gruppe, bestehend aus den natürlichen Aminosäuren, Polyamiden, erhältlich durch Polykondensation einer Dicarbonsäure mit 4 bis 6 C-Atomen und einem Diamin mit 4 bis 10 C-Atomen, Verbindungen der Formeln IV a und IVb

(IIa) (IIb) in which p is an integer from 1 to 1500 and r is an integer from 1 to 4, and G is a radical selected from the group consisting of phenylene, - (CH ₂ ) _q -, where q is an integer from 1 to 5, -C (R) H- and -C (R) HCH ₂ , where R is methyl or ethyl is at least one amino-C ₂ - to C ₂ alkanol or at least one amino-C ₅ -C Ci ₀ cycloalkanol, or mixtures thereof c4) at least one diamino-Crbis C ₈ -alkane c5) at least one 2,2'-bisoxazoline of the general formula III

wherein R ^{1 is} a single bond, a (CH ₂ ) _Z alkylene group, where z = 2, 3 or 4, or a phenylene group c6) at least one aminocarboxylic acid selected from the group consisting of the natural amino acids, polyamides obtainable by polycondensation of a Dicarboxylic acid having 4 to 6 carbon atoms and a diamine having 4 to 10 carbon atoms, compounds of the formulas IV a and IVb

in der R³ für Wasserstoff, Ci-C₆-Alkyl, C₅-C₈-Cycloalkyl, unsubstituiertes oder mit Ci-C₄-Alkylgruppen bis zu dreifach substituiertes Phenyl oder für Tetrahydrofuryl steht, oder Mischungen aus c1 bis c6 (IVa) (IVb) in which s is an integer from 1 to 1500 and t is an integer from 1 to 4, and T is a radical selected from the group consisting of phenylene, - (CH ₂ ) _U -, wherein u is an integer from 1 to 12, -C (R ² ) H- and -C (R ² ) HCH ₂ , wherein R ^{2 is} methyl or ethyl, and polyoxazolines having the repeating unit V

in which R ^{3 is} hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₈ -cycloalkyl, phenyl which is unsubstituted or substituted up to three times by C 1 -C ₄ -alkyl or is tetrahydrofuryl, or mixtures of c1 to c6

 and

D) a component selected from d1) at least one compound having at least three groups capable of ester formation, d2) at least one isocyanate d3) at least one divinyl ether or mixtures of d1) to d3). In a preferred embodiment, the acid component A of the partially aromatic polyesters contains from 30 to 70, in particular from 40 to 60, mol% of a1 and from 30 to 70, in particular from 40 to 60, mol% of a2.

As aliphatic acids and the corresponding derivatives a1 are generally those having 2 to 10 carbon atoms, preferably 4 to 6 carbon atoms, into consideration. They can be both linear and branched. In the context of the present Cycloaliphatic dicarboxylic acids which can be used according to the invention are generally those having 7 to 10 carbon atoms and especially those having 8 carbon atoms. In principle, however, it is also possible to use dicarboxylic acids having a larger number of carbon atoms, for example having up to 30 carbon atoms.

Examples which may be mentioned are malonic acid, succinic acid, 2-methylsuccinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, fumaric acid, 2,2-dimethylglutaric acid, suberic acid, 1,3-cyclopentanedicarboxylic acid, 1 , 4-cyclohexanedicarboxylic acid, 1, 3-cyclohexanedicarboxylic acid, diglycolic acid, itaconic acid, maleic acid and 2,5-norbornanedicarboxylic acid.

Suitable ester-forming derivatives of the abovementioned aliphatic or cycloaliphatic dicarboxylic acids which are likewise usable are, in particular, the di-Ci- to C ₆ -alkyl esters, such as dimethyl-, diethyl-, di-n-propyl, di-isopropyl, di-n- butyl, di-iso-butyl, di-t-butyl, di-n-pentyl, di-iso-pentyl or di-n-hexyl esters. Anhydrides of dicarboxylic acids can also be used.

The dicarboxylic acids or their ester-forming derivatives may be used singly or as a mixture of two or more thereof.

Succinic acid, adipic acid, azelaic acid, sebacic acid, brassylic acid or their respective ester-forming derivatives or mixtures thereof are preferably used. Succinic acid, adipic acid or sebacic acid or their respective ester-forming derivatives or mixtures thereof are particularly preferably used. Particular preference is given to using adipic acid or its ester-forming derivatives, such as their alkyl esters or mixtures thereof. As aliphatic dicarboxylic acid sebacic acid or mixtures of sebacic acid with adipic acid are preferably used when polymer blends with "hard" or "brittle" components ii) such as polyhydroxy butyrate or in particular polylactide are prepared. As aliphatic dicarboxylic acid, succinic acid or mixtures of succinic acid with adipic acid are preferably used when polymer blends with "soft" or "tough" components ii) are prepared, such as Polyhydroxybuyratcovaleriat.

Succinic acid, azelaic acid, sebacic acid and brassylic acid also have the advantage that they are available as renewable raw materials.

As aromatic dicarboxylic acid a2 are generally those with 8 to 12 carbon atoms, and preferably those with 8 carbon atoms mentioned. Examples include terephthalic acid, isophthalic acid, 2,6-naphthoic acid, 2,5-furan dicarboxylic acid and 1, 5-naphthoic acid and ester-forming derivatives thereof. In particular, the di-C 1 -C ₆ -alkyl esters, for example dimethyl, diethyl, di-n-propyl, di-isopropyl, di-n-butyl, di-iso-butyl, di-t-butyl, Di-n-pentyl, di-iso-pentyl or di-n-hexyl esters to name. The anhydrides of dicarboxylic acids a2 are also suitable ester-forming derivatives.

In principle, however, it is also possible to use aromatic dicarboxylic acids a2 having a larger number of carbon atoms, for example up to 20 carbon atoms.

The aromatic dicarboxylic acids or their ester-forming derivatives a2 may be used singly or as a mixture of two or more thereof. Particularly preferred is terephthalic acid or its ester-forming derivatives such as dimethyl terephthalate used.

The sulfonate group-containing compound is usually an alkali metal or alkaline earth metal salt of a sulfonate-containing dicarboxylic acid or its ester-forming derivatives, preferably alkali metal salts of 5-sulfoisophthalic acid or mixtures thereof, particularly preferably the sodium salt.

According to one of the preferred embodiments, the acid component A contains from 40 to 60 mol% of a1, from 40 to 60 mol% of a2 and from 0 to 2 mol% of a3. According to a further preferred embodiment, the acid component A contains from 40 to 59.9 mol% a1, from 40 to 59.9 mol% a2 and from 0.1 to 1 mol% a3, in particular from 40 to 59.8 mol -% a1, from 40 to 59.8 mol% a2 and from 0.2 to 0.5 mol% a3.

In general, the diols B are selected from branched or linear alkanediols having 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms, or cycloalkanediols having 5 to 10 carbon atoms.

Examples of suitable alkanediols are ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 2-butanediol, 1, 4-butanediol, 1, 5-pentanediol, 2,4-dimethyl-2-ethylhexane-1, 3 diol, 2,2-dimethyl-1, 3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 2,2,4- Trimethyl-1, 6-hexanediol, in particular ethylene glycol, 1, 3-propanediol, 1, 4-butanediol and 2,2-dimethyl-1, 3-propanediol (neopentyl glycol); Cyclopentanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol or 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Particular preference is given to 1,4-butanediol, in particular in combination with adipic acid as component a1) and 1,3-propanediol, in particular in combination with sebacic acid as component a1). 1, 3-propanediol and 1, 4-butanediol also have the advantage that they are used as nach- growing raw materials are accessible. It is also possible to use mixtures of different alkanediols.

Depending on whether an excess of acid or OH end groups is desired, either component A or component B can be used in excess. According to a preferred embodiment, the molar ratio of the components A used to B in the range of 0.4: 1 to 1, 5: 1, preferably in the range of 0.6: 1 to 1, 1: 1. In addition to the components A and B, the polyesters on which the polyester mixtures according to the invention are based can contain further components.

Preferred dihydroxy compounds c1 are diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol and polytetrahydrofuran (polyTHF), particularly preferably diethylene glycol, triethylene glycol and polyethylene glycol, mixtures of which or compounds having different variables n (see formula I), For example, polyethylene glycol containing propylene units (n = 3), for example, obtainable by polymerization according to known methods of first ethylene oxide and then with propylene oxide, more preferably a polymer based on polyethylene glycol, with different variables n, wherein units formed of ethylene oxide predominate. The molecular weight (M _n ) of the polyethylene glycol is usually selected in the range from 250 to 8000, preferably from 600 to 3000 g / mol. According to one of the preferred embodiments are from 15 to 98, preferably 60 to 99.5 mol% of the diols B and 0.2 to 85, preferably 0.5 to 30 mol% of the dihydroxy compounds c1, based on the molar amount of B and c1, used for the preparation of partially aromatic polyesters. In a preferred embodiment, c2) is used as hydroxycarboxylic acid: glycolic acid, D-, L-, D, L-lactic acid, 6-hydroxyhexanoic acid, whose cyclic derivatives such as glycolide (1,4-dioxane-2,5-dione), D , L-dilactide (3,6-dimethyl-1,4-dioxane-2,5-dione), p-hydroxybenzoic acid and its oligomers and polymers such as poly-3-hydroxybutyric acid, poly-3-hydroxyvaleric acid, polylactide ( for example, available as Ingeo® from Natureworks LLC) and a mixture of poly-3-hydroxybutyric acid and poly-3-hydroxy-valeric acid (the latter is available under the name Enmat ^® from Tianan), particularly preferred for the preparation Partially aromatic polyesters are the low molecular weight and cyclic derivatives thereof. The hydroxycarboxylic acids can be used, for example, in amounts of from 0.01 to 50, preferably from 0.1 to 40,% by weight, based on the amount of A and B. As amino-C ₂ -Ci2-alkanol or amino-C ₅ -Cio-cyloalkanol (component c3), which should also include 4-Aminomethylcyclohexanmethanol, it is preferred to use amino-C ₂ -C ₆ -alkanols such as 2-aminoethanol, 3rd Aminopropanol, 4-aminobutanol, 5-aminopentanol, 6-aminohexanol and amino C ₅ -C ₆ cycloalkanols such as aminocyclopentanol and aminocyclohexanol or mixtures thereof.

As diamino-Ci-Cs-alkane (component c4) are preferably used diamino-C ₄ -C ₆ alkanes such as 1, 4-diaminobutane, 1, 5-diaminopentane and 1, 6-diaminohexane (hexamethylenediamine, "HMD ").

According to a preferred embodiment, from 0.5 to 99.5 mol%, preferably 0.5 to 50 mol%, of c3, based on the molar amount of B, and from 0 to 50, preferably from 0 to 35 mol% , c4, based on the molar amount of B, are used for the preparation of semiaromatic polyesters see.

The 2,2'-bisoxazolines c5 of general formula III are generally prepared by the process of Angew. Chem. Int. Edit., Vol. 1 1 (1972), pp. 287 to 288 available. Particularly preferred bisoxazolines are those in which R ^{1 is} a single bond, a (CH ₂ ) _Z -alkylene group, where z = ₂ , 3 or 4, such as methylene, ethane-1, 2-diyl, propane-1, 3-diyl, propane -1, 2-diyl, or a phenylene group. Particularly preferred bisoxazolines are 2,2'-bis (2-oxazoline), bis (2-oxazolinyl) methane, 1, 2-bis (2-oxazolinyl) ethane, 1, 3-bis (2-oxazolinyl) propane or 1,4-bis (2-oxazolinyl) butane, in particular 1,4-bis (2-oxazolinyl) benzene, 1,2-bis (2-oxazolinyl) benzene or 1,3-bis (2-oxazolinyl) called benzene.

For the preparation of partially aromatic polyesters, for example, from 70 to 98 mol% B, to 30 mol% c3 and 0.5 to 30 mol% c4 and 0.5 to 30 mol% c5, in each case based on the sum of the molar amounts components B, c3, c4 and c5. According to another preferred embodiment, it is possible to use from 0.1 to 5, preferably 0.2 to 4 wt .-% c5, based on the total weight of A and B, use.

As component c6 natural aminocarboxylic acids can be used. These include valine, leucine, isoleucine, threonine, methionine, phenylalanine, tryptophan, lysine, alanine, arginine, aspartic acid, cysteine, glutamic acid, glycine, histidine, proline, serine, tyrosine, asparagine or glutamine.

Preferred aminocarboxylic acids of the general formulas IVa and IVb are those in which s is an integer from 1 to 1000 and t is an integer from 1 to 4, preferably 1 or 2 and T is selected from the group phenylene and - (CH ₂ ) _U -, where u is 1, 5 or 12.

Furthermore, c6 can also be a polyoxazoline of the general formula V. C6 can also be a mixture of different aminocarboxylic acids and / or polyoxazolines.

According to a preferred embodiment, c6 can be used in amounts of from 0.01 to 50, preferably from 0.1 to 40,% by weight, based on the total amount of components A and B.

Other components which may optionally be used to prepare the partially aromatic polyesters include compounds d1 which contain at least three groups capable of ester formation.

The compounds d1 preferably contain from three to ten functional groups which are capable of forming ester or amide bonds. Particularly preferred compounds d1 have three to six functional groups of this kind in the molecule, in particular three to six hydroxyl groups and / or carboxyl groups and / or amino groups. Examples include:

Tartaric acid, citric acid, malic acid;

 Trimethylolpropane, trimethylolethane;

 pentaerythritol;

polyether triols;

 glycerol;

 trimesic;

 Trimellitic acid, anhydride;

 Pyromellitic acid, dianhydride and

Hydroxyisophthalic.

The compounds d1 are generally used in amounts of 0.01 to 15, preferably 0.05 to 10, particularly preferably 0.1 to 4 mol%, based on the component A.

As component d2, one or a mixture of different isocyanates are used. It is possible to use aromatic or aliphatic diisocyanates. However, it is also possible to use higher functional isocyanates. Among an aromatic diisocyanate d2 are in the context of the present invention especially Toluylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthylene-1, 5-diisocyanate or xylylene understood.

Of these, 2,2'-, 2,4'- and 4,4'-diphenylmethane diisocyanate as component d2 are particularly preferred. In general, the latter diisocyanates are used as a mixture. As a trinuclear isocyanate d2 is also tri (4-isocyanophenyl) methane into consideration. The polynuclear aromatic diisocyanates are obtained, for example, in the preparation of mono- or binuclear diisocyanates.

In minor amounts, e.g. up to 5% by weight, based on the total weight of component d2, of component d2 may also contain urethione groups, for example for capping the isocyanate groups.

In the context of the present invention, an aliphatic diisocyanate d2 is, above all, linear or branched alkylene diisocyanates or cycloalkylene diisocyanates having 2 to 20 carbon atoms, preferably 3 to 12 carbon atoms, e.g. 1, 6-hexamethylene diisocyanate, isophorone diisocyanate or methylene-bis (4-isocyanatocyclo-hexane) understood. Particularly preferred aliphatic diisocyanates d2 are 1,6-hexamethylene diisocyanate and isophorone diisocyanate. Preferred isocyanurates include the aliphatic isocyanurates derived from alkylene diisocyanates or cycloalkylene diisocyanates having 2 to 20 carbon atoms, preferably 3 to 12 carbon atoms, e.g. Isophorone diisocyanate or methylene bis (4-isocyanatocyclohexane), derived. The alkylene diisocyanates can be both linear and branched. Particular preference is given to isocyanurates based on n-hexamethylene diisocyanate, for example cyclic trimers, pentamers or higher oligomers of n-hexamethylene diisocyanate.

In general, the component d2 is used in amounts of from 0.01 to 5, preferably from 0.05 to 4, mol%, particularly preferably from 0.1 to 4, mol%, based on the sum of the molar amounts of A and B.

In general, all conventional and commercially available divinyl ethers can be used as the divinyl ether d3. Preference is given to using 1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether or 1,4-cyclohexanedimethanol divinyl ether or mixtures thereof. The divinyl ethers are preferably used in amounts of from 0.01 to 5, in particular from 0.2 to 4,% by weight, based on the total weight of A and B.

Examples of preferred partially aromatic polyesters are based on the following components

A, B, d1

 A, B, d2

 A, B, d1, d2

A, B, d3

 A, B, d

 A, B, d, d3

 A, B, c3, c4

 A, B, c3, c4, c5

A, B, d1, c3, c5

 A, B, c3, d3

 A, B, c3, d1

 A, B, d, c3, d3

 A, B, c2

Of these, partially aromatic polyesters based on A, B, d1 or A, B, d2 or on A, B, d1, d2 are particularly preferred. In another preferred embodiment, the partially aromatic polyesters are based on A, B, c3, c4, c5 or A, B, d1, c3, c5. The abovementioned partially aromatic polyesters and the polyester mixtures according to the invention are generally biodegradable.

For the purposes of the invention, the feature "biodegradable" for a substance or a mixture of substances is fulfilled if this substance or the mixture of substances in at least one of the three methods defined in DIN V 54900-2 (pre-standard, September 1998) a percentage Degree of biodegradation of at least 60%.

In general, biodegradability causes the polyester blends to disintegrate in a reasonable and detectable time. Degradation can be effected enzymatically, hydrolytically, oxidatively and / or by the action of electromagnetic radiation, for example UV radiation, and is usually effected for the most part by the action of microorganisms such as bacteria, yeasts, fungi and algae. The biodegradability can be quantified, for example, by mixing polyesters with compost and storing them for a certain period of time. For example, in accordance with DIN EN 13432 or DIN V 54900-2, method 3, C0 ₂ -free air through matured compost during composting allowed to flow and this subjected to a defined temperature program. Hereby, the biodegradability is determined by the ratio of the net C0 ₂ release of the sample (after deduction of C0 ₂ release by the compost without sample) to the maximum C0 ₂ release of the sample (calculated from the carbon content of the sample) percentage degree of biodegradation defined. Biodegradable polyesters (mixtures) usually show clear degradation phenomena such as fungal growth, cracking and hole formation after only a few days of composting. Other methods of determining biodegradability are described, for example, in ASTM D 5338 and ASTM D 6400.

The preparation of partially aromatic polyesters is known per se or can be carried out by methods known per se.

The preferred partially aromatic polyesters are characterized by a molecular weight (M _n ) in the range from 1000 to 100,000, in particular in the range from 9,000 to 75,000 g / mol, preferably in the range from 10,000 to 50,000 g / mol and a melting point in the range from 60 to 170 , preferably in the range of 80 to 150 ° C.

The abovementioned partially aromatic polyesters may have hydroxyl and / or carboxyl end groups in any ratio. The abovementioned partially aromatic polyesters can also be end-group-modified. For example, OH end groups can be acid-modified by reaction with phthalic acid, phthalic anhydride, trimellitic acid, trimellitic anhydride, pyromellitic acid or pyromellitic anhydride.

In principle, homopolymers or copolyesters from the group of polylactide, polycaprolactone, polyhydroxyalkanoates and polyesters of aliphatic dicarboxylic acids and aliphatic diols are suitable as components ii of the biodegradable polyester mixtures. Preferred components ii are polylactide (PLA) and / or its stereo complex, polyhydroxyalkanoates (PHA) and polybutylene succinates and its copolyesters, and in particular poly-3-hydroxybutyrate (PHB) poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), Poly-3-hydroxybutyrate-co-4-hydroxybutyrate (P3HB-co-4HB), poly-3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBH), polybutylene succinate (PBS), polybuylene succinate adipate (PBSA) and polybutylene succinatlactat. In particular, products such as Ingeo® (polylactide from Natureworks LLC), Mirel® (poly-3-hydroxybutyrate-co-4-hydroxybutyrate from Telles / Metabolix), Aonilex® (poly-3-hydroxybutyrate-co-3-) hydroxyhexanoate from the company Kaneka) Enmat® (poly-3-hydroxybutyrate-co-3-hydroxyvalerate from Tianan), Bionolle® (polybutylene) succinate and polybutylene succinate adipates from Showa Denko) and GSPLa® (polybutylene succinate lactate from Mitsubishi).

Component iii according to the invention comprises a) an epoxide group-containing copolymer based on styrene, acrylate and / or methacrylic acid ester, b) a bisphenol A epoxide or c) an epoxide group-containing natural oil, fatty acid ester or fatty acid amide.

An epoxy group-containing copolymer based on styrene, acrylic ester and / or methacrylic acid ester is preferably used. In general, the compounds have two or more epoxide groups in the molecule. Particularly suitable are oligomeric or polymeric, epoxidized compounds, for example di- or polyglycidyl esters of di- or polycarboxylic acids or di- or polyglycidyl ethers of diols or polyols, or copolymers of styrene and glycidyl (meth) acrylates, as described, for example, by Fa. Johnson Polymer under the trademark Joncryl® ADR 4368 are sold.

Further preferred components iii are compounds which contain at least one carbon-carbon double or triple bond and at least one epoxide group in the molecule. Particularly suitable are glycidyl acrylate and glycidyl methacrylate.

Furthermore, as component iii) c) epoxide-containing (epoxidized) natural oils or fatty acid esters are preferred. By natural oils is meant, for example, olive oil, linseed oil, soybean oil, palm oil, peanut oil, coconut oil, tang oil, cod liver oil or a mixture of these compounds. Particularly preferred are epoxidized soybean oil (eg Merginat® ^® ESBO from Hobum, Hamburg, or Edenol ^® B 316 from Cognis, Dusseldorf). Particular preference is given to combining the structural types a) and c) as component iii). The combination of Joncryl ^® ADR 4368 (structural type a)) and Merginat® ^® ESBO (structural type c) is carried out in more detail in the examples are particularly preferred.

Component iii) is in 0.1 to 15 wt .-%, preferably in 0.1 to 10 wt .-%, and particularly preferably in 0.1 to 2 wt .-%, based on the total weight of the components i) and ii).

The polyester mixtures according to the invention usually comprise from 5 to 90% by weight, preferably from 20 to 90% by weight, particularly preferably from 30 to 90% by weight, in particular from 40 to 85% by weight of component i and from 10 to 95 wt .-%, preferably from 10 to 80 wt .-%, particularly preferably from 10 to 70 wt .-%, most preferably from 15 to 60 wt .-% component ii, wherein the weight in each case based on the total weight of components i and ii and together give 100 wt .-%.

Bubble stability is of great importance for the production of extruded thermoplastics such as films. Mixtures in which component i forms a preferably continuous phase or at least a co-continuous phase and component ii is embedded in this area in separate regions have good bubble stability. In order for component i to form a continuous phase, the mixtures generally have more than 40% by weight, preferably more than 50% by weight, of component i, based in each case on the total weight of components i and ii.

For the production of moldings for example for injection molding, polyester blends with high polyhydroxybutyrate (PHB) or in particular polylactide (PLA) moiety (component ii) can be used. Usually, mixtures of 60 to 95 wt .-% component can be realized here.

If, as component i), polyesters are used which contain sebacic acid or mixtures of sebacic acid with adipic acid as dicarboxylic acid (component a1), the proportion of the polyester in the mixtures with component ii) can even be reduced below the 10% by weight limit become.

In addition, the polyester mixtures according to the invention usually contain from 0.1 to 15 wt .-%, preferably from 0.1 to 10 wt .-%, particularly preferably from 0.1 to 2 wt .-% component iii, wherein the weight percent each on the total weight of components i and ii are related.

As component iv-1, the polyester mixture according to the invention contains from 0.1 to 5% by weight, preferably from 0.2 to 3% by weight, particularly preferably from 0.2 to 2% by weight, in particular from 0.4 to 2 % By weight, based on the sum of components i and ii, of one or more finely divided, layered silicates, preferably clay minerals, particularly preferably montmorillonite-containing clay minerals whose surface is modified with one or more quaternary ammonium salts and / or phosphonium salts and / or sulfonium salts.

Preferred clay minerals are natural montmorillonites and bentonites

wobei die Symbole folgende Bedeutungen haben: The minerals used are modified on the surface with one or more quaternary ammonium, phosphonium and / or sulfonium salts. Preference is given to ammonium salts which contain at least one longer-chain (> C12) saturated or mono- or polyunsaturated alkyl or fatty acid radical. Preferred ammonium salts are those of the formula (VI)

where the symbols have the following meanings:

R ¹ is identical or different and is a straight-chain, branched or cyclic, saturated or mono- or polyunsaturated hydrocarbon radical having 1 to 12, preferably 1 to 4, C atoms which is unsubstituted or contains one or more

Substituted OH groups;

R ² is identical or different and is a straight-chain or branched, saturated or mono- or polyunsaturated hydrocarbon radical having 13 to 24 C atoms; n is 0, 1, 2, 3 or 4, preferably 1 or 2 and

X is an anion, preferably Cl.

The longer-chain radicals R ² used are preferably hydrogenated beef tallow ("HT") or tallow ("T"), ie a mixture of relatively long-chain fatty acid radicals (eg ~ 65% Ci ₈ , ~ 30% Ci ₆ , ~ 5% Ci ₄ ).

Particularly preferred are the compounds

(CH ₃ ) ₂ N (HT) ₂ Cl (VI-1) and

(HIGH ₂ -CH ₂ ) ₃ N (T) CI (VI-2).

For the modification of the phyllosilicates with phosphonium salts, all phosphonium salts with four organic radicals are suitable, as described in DE 10353890 A1. However, the phosphonium salts exclusively aliphatic groups have the disadvantage of difficult production, since the starting materials are easily inflammable lent. Therefore, phosphonium salts having at least two aromatic groups are preferred. Particularly preferred are phosphonium salts having three or four arbitrarily substituted aromatic radicals. These can be prepared relatively easily from triphenylphosphines according to the prior art. The aromatic radicals of the cations with phosphorus-containing substituents and in particular of the aromatic phosphonium salts can be unsubstituted and / or optionally substituted, with alkyl groups being preferred. As aromatic radicals, phenyl radicals and their derivatives are particularly preferred. The substitution of at least one of the phenyl rings with a branched or unbranched alkyl group having at least three carbon atoms is particularly preferred here, since in this way the distance of the silicate layers is increased, which is favorable for the production of the nanocomposites. This effect is especially pronounced when the alkyl group is in the para position to the organically substituted cation. Due to the increased distance of the silicate layers, the organically modified layer minerals can be distributed particularly finely in the binder.

In the case where only three aromatic groups are attached to the phosphorus in the aromatic phosphonium salts, the fourth group is a cyclic, branched or unbranched alkyl group or an aralkyl group (e.g., a benzyl group). Particularly preferred are linear or branched alkyl chains having at least five carbon atoms and benzyl groups. Nanocomposites containing layered silicates modified with phosphonium ions based on triphenylphosphane are particularly preferred because of their synthetically good accessibility. In these substances, the fourth radical on the phosphor is preferably a linear or branched, arbitrarily substituted alkyl group or arbitrarily substituted aromatic rings. Suitable aromatic radicals of the phosphonium ion are in particular substituted or unsubstituted phenyl or biphenyl groups. Of these, the unsubstituted main body are particularly preferred. Tetraphenylphosphonium and triphenyl (p-biphenyl) phosphonium are therefore, in addition to the triphenylphosphonium salts with a long alkyl chain, particularly preferred cations for incorporation into the layered silicates.

Sulfonium salts for the modification of bentonites are e.g. described in EP-A 0 079 972.

Particularly preferred as component iv-1 is a nanodispergierbares layered silicate based on natural bentonites, modified with ammonium salt (VI-1), which is available for example under the name Nanofil ^® 5 or Cloisite ^® 20A from Rockwood Clay Additives GmbH, Moosburg, Germany.

Further preferred as component iv-1 is a nanodispergierbares natural montmorillonite modified with ammonium salt (VI-2), which is available for example under the name Nanofil ^® 9 of Rockwood Clay Additives GmbH.

Component iv-2) is a nanoparticulate silicon dioxide prepared by flame-pyrolytic, the surface of which is hydrophobically modified and has a number-average particle diameter of the primary particles of from 1 to 20 nm, preferably from 1 to 15 nm.

In a preferred embodiment, component iv-2) is hydrophobically modified by a surface modifier, preferably an organosilane. The surface modification can be carried out by contacting the nanoparticles, preferably as a suspension or as such, with a surface modifier, for example by spraying. In particular, it is possible first to spray the nanoparticles with water and then with the surface modifier. The spraying can also be done in reverse order. The water used may be acidified with an acid, for example hydrochloric acid, to a pH of 7 to 1. If more surface modifiers are used, they may be applied as a mixture or separately, simultaneously or sequentially.

The surface modifier (s) may be dissolved in suitable solvents. After the spraying is finished, mixing can be continued for 5 to 30 minutes. Preferably, the mixture is then thermally treated at a temperature of 20 to 400 ° C over a period of 0.1 to 6 hours. The thermal treatment can be carried out under protective gas, such as nitrogen.

An alternative method of surface modification of the nanoparticles can be accomplished by treating the nanoparticles with the surface modifier in vapor form and then thermally treating the mixture at a temperature of 50 to 800 ° C for a period of 0.1 to 6 hours. The thermal treatment can be carried out under protective gas, such as nitrogen. The temperature treatment can also be carried out in several stages at different temperatures. The application of the surface modifier (s) can be carried out with single-component, double-material or ultrasound nozzles.

The surface modification can be carried out continuously or batchwise in heatable mixers and dryers with sprayers. Suitable devices may be, for example: plowshare mixers, plate, fluidized bed or fluid bed dryers.

Surface modifiers which can be used advantageously in the context of the present invention are described in DE 10 2007 035 951 A1 in paragraph [0015], the content of which is hereby fully incorporated by reference.

Preferably can be used as surface modifiers following silanes: octyltrimethoxysilane, octyltriethoxysilane, hexamethyldisilazane, 3-methacryloxy propyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, dimethylpolysiloxane, glycidyloxypropyltrimethoxysilane, glycidyloxypropyltriethoxysilane, Nonafluorohexyltrimethoxysilan, Tridecaflourooctyl- trimethoxysilane, tridecaflourooctyltriethoxysilane, aminopropyltriethoxysilane, hexamethyldisilazane.

Hexamethyldisilazane, hexadecyltrimethoxysilane, dimethylpolysiloxane, octyltrimethoxysilane and octyltriethoxysilane are particularly preferably used.

In particular, hexamethyldisilazane, octyltrimethoxysilane and hexadecyltrimethoxysilane are used, most preferably hexamethyldisilazane. Preferably component iv is component iv-1.

The biodegradable polyester mixtures according to the invention may contain further additives known to the person skilled in the art. In particular, stabilizers, nucleating agents, lubricants and anti-blocking agents such as stearates (in particular calcium stearate), waxes such as, for example, beeswax or beeswax esters; Plasticizers such as citric acid esters (especially acetyl tributyl citrate), glyceric acid esters such as triacetylglycerol or ethylene glycol derivatives; Surfactants such as polysorbates, palmitates, laurates; Antistatic agents, antifog agents or dyes understood. The additives are used in concentrations of from 0 to 15% by weight, in particular from 1 to 10% by weight, based on the polyester mixtures according to the invention.

Suitable fillers other than component iv) include, for example, inorganic or organic fillers such as calcium carbonate, talc, silicates, kaolin, glimmer, wollastonites or cellulose-containing fibers such as cotton, flax, hemp or nettle fibers. Preferred fillers are talc and calcium carbonate. The fillers are used in concentrations of from 0 to 50% by weight, in particular from 1 to 30% by weight, based on the polyester mixtures according to the invention. It has been found that especially at low (15 to 25%) portions of component ii by adding mineral fillers v, in particular talc and / or calcium carbonate, the tear propagation resistance can be markedly improved. So there are synergistic effects between the components iv and v. Preference is therefore also given to polyester mixtures containing

 From 75 to 85% by weight of component i;

 15 to 25 wt .-% of component ii;

 0.5 to 3% by weight of component iii;

 0.4 to 2% by weight of component iv, in particular iv-1, and

15 to 30 wt .-% of component v, in particular talc or calcium carbonate. The preparation of the biodegradable polyester mixtures according to the invention from the individual components can be carried out by known processes (see, for example, EP 792 309 and US Pat. No. 5,883,199). For example, all components i, ii, iii and iv can be mixed and reacted in one process step in mixing devices known to those skilled in the art, for example kneaders or extruders at elevated temperatures, for example from 120 ° C. to 250 ° C. The reaction is preferably carried out in the presence of a radical initiator.

The preparation of the biodegradable polyester mixtures according to the invention advantageously takes place according to the process described in WO 2006/074815.

For this purpose, in a first step 1 to 50 wt .-%, preferably 5 to 35 wt .-% of component iii with 50 to 99 wt .-% and preferably 65 to 95 wt .-% of component i at temperatures of 1 10th to 145 ° C - preferably 120 to 140 ° C - mixed to a Verzweigerbatch. At these temperatures, a homogeneous blend is obtained without appreciable molecular weight build-up. The thus obtained Verzweigerbatch can be stored easily at room temperature. In a second step, the desired composition can be adjusted by adding the branching agent to component ii and optionally further component i. This compounding step is carried out at 150 to 250 ° C, preferably at 160 to 190 ° C. The temperatures in the compounding step can generally be reduced and thus avoid decomposition of sensitive biopolymers such as polyhydroxybutyrates by using an activator selected from the group consisting of: zinc, tin, titanium compound and CrCl ₂ -alkyltriphenylphosphonium halide. Typical branching batches contain 5 to 35% by weight, preferably 10 to 20% by weight of component iii) and 65 to 95% by weight, preferably 80 to 90% by weight of component i. Surprisingly, these branching batches have proved to be advantageous over corresponding branching batches consisting of component ii) and iii). The branching batches are the subject of the present invention. It is clear from examples 4 to 6 below that the branching batches according to the invention comprising components i) and iii) have advantages over the partially available branching batches (eg polylactide and glycidyl methacrylate) with regard to the flow rate of the polyester mixtures formed. In addition, the branching batches according to the invention are distinguished by excellent storage stability. Examples of branching batches according to the invention are:

Component i), polyester produced by condensation of:

Adipic acid / terephthalic acid and 1, 4-butanediol (. Eg Ecoflex F Blend ^® A1200);

Adipic acid / terephthalic acid and 1,3-propanediol;

Succinic acid / terephthalic acid and 1,4-butanediol;

Succinic acid / terephthalic acid and 1, 3-propanediol;

Sebacic acid / terephthalic acid and 1,4-butanediol;

Sebacic acid / terephthalic acid and 1, 3-propanediol

Azelaic acid / terephthalic acid and 1,4-butanediol;

Brassylic acid / terephthalic acid and 1,4-butanediol; and

Component iii) styrene glycidyl (meth) acrylate copolymer (for example, Joncryl ADR 4368 ^® from BASF)..

For the preparation of polyester blends with a high proportion of "hard" or "brittle" component ii) such as> 50 wt .-% polyhydroxy butyrate or in particular polylactide, the following procedure has proven to be particularly advantageous. It is prepared as described above either by mixing the components i), ii) and iii) or in two steps by mixing one of the above-mentioned Verzweigerbatches with component ii) and optionally further component i) an intermediate compound, preferably 48 to 60 wt. % Component i), 40 to 50 wt .-% component ii) and 0.5 to 2 wt .-% component iii). In an additional step, this intermediate compound is then mixed with further component ii) until the desired content of component ii) in the polyester mixture is established. The polyester blend produced by this three-stage process is excellently suitable for the production of biodegradable, impact-resistant polyester blends.

As aliphatic dicarboxylic acid sebacic acid or mixtures of sebacic acid with adipic acid are preferably used when polymer blends with a high proportion of "hard" or "brittle" components ii) are prepared, such as polyhydroxy butyrate or in particular polylactide.

Advantageously, only a part of the Ecoflex / PLA formulation is equipped with a compatibilizer concentrate. Examples of a so-called compatibilizer batch are the above-mentioned branching batches and intermediate compounds. This saves compounding costs:

The biodegradable polyester mixtures according to the invention are particularly suitable for the production of films, films, moldings or fibers. The preparation can be carried out by methods known to the person skilled in the art. A particular field of application of the biodegradable polyester mixtures relates to the use for the production of films with high tear propagation resistance, in particular for mulched films in agriculture, biowaste bags, carrier bags of various wall thicknesses and shapes, fruit sachets and food packaging.

With the aid of the biodegradable polyester mixtures according to the invention, biodegradable polymer mixtures are obtained which can be processed without problems (bubble-stable) to form films which are particularly tear-resistant. Examples:

Application-technical measurements:

The homogeneity of the mixtures of components i, ii, iii, iv and v and of the mixtures prepared for comparison was determined by optical assessment of the blown films. Poorly dispersed filler agglomerates appeared in the form of an increased speckle level, which was classified into the following categories: ++ (barely speckled), + (low specks), o (raised speckle level), - (many specks), - (very many specks ).

The tear propagation resistance was determined by means of an Elmendorf test according to EN ISO 6383-2: 2004 with a device from the company ProTear on test specimens with a constant radius (43 mm crack length) on blown films both in the film longitudinal direction and in the film transverse direction.

Starting Materials: i- 1: part Aromatic polyester Ecoflex ^® F Blend A1200 from BASF i-2: partially aromatic polyester (from sebacic acid and terephthalic acid preparation, see Example 5c in WO 2010/034710] II-1: aliphatic polyester, polylactide PLA 4042D of Fa. NatureWorks LLC iii-1. batch A: 20 wt .-% hydrochloric masterbatches of Joncryl ADR 4368 in Ecoflex ^® F

Blend B1300 (preparation see EP-A 1838784) iii- 2: Batch B: 10 wt .-% hydrochloric masterbatch of erucamide in Ecoflex ^® F Blend

B1300 iv 2-1: Aerosil R8200 from Evonik iv-2-2: Aerosil 380 from Evonik

iv-1 -1: Nanofil 5 from the company Rockwood Clay Additives GmbH, Moosburg, Germany iv-1-2: Nanofil 9 from the company Rockwood Clay Additives GmbH, Moosburg, Germany v-1: CaC0 ₃ from the type Hydrocarb 75 T OG of the company OMYA

v-2: talc with a mean particle diameter of 1.7 microns and a topcut (d98%) of 8 microns from Mondo Minerals

Manufacturing instructions of the compounds:

For the examples and comparative examples given in Table 1, the amounts stated in Table 1 were compounded on a Werner & Pfleiderer MC-26 extruder at a zone temperature of 200-250 ° C. The components i, ii, iii and iv are metered by coldfeed in zone 0, components v are added in zone 4 by Seitenfeeder and back in zone 3, the registered air is removed by a vacuum degassing.

Production of tubular films:

The blown film line was run on a 25D extruder with a 45mm screw equipped with a grooved feed zone and a three zone screw with shear and mixing section. The feed zone was cooled at maximum throughput with cold water. The zone temperatures were chosen so that the melt temperature was between 170 and 190 ° C. The die temperatures ranged from 165 to 185 ° C. The nozzle diameter was 75mm, the gap width 0.8mm. The blow-up ratio of 3.5: 1 resulted in a lying width of the film tube of 412 mm.

Examples 1 to 9 according to the invention are distinguished by higher tear propagation strengths compared with comparative examples 1 to 3 known in the prior art, with simultaneous good dispersion and low to moderate number of blisters of the blown films. Although increased elevated tear strengths occur at elevated concentrations of component iv (Comparative Examples 4 and 5 and 7 and 8), the dispersion of the nanofillers becomes worse and there is a high to very high speck content in the blown films, which makes them commercially viable Application less suitable. The advantageous effect of the branching agent A on the film properties shows the comparison between Comparative Examples 2 and 1 and between Example 4 and Comparative Example 6, the latter clearly demonstrating the positive effect of component iv according to the invention on the tear propagation resistance.

At a lower content of component ii-1 of only 18% or 10% (based on the sum of all organic components i, ii) improve the tear strength of the blown films by adding the Nanofü II substances iv-1 -1 only slightly - Fügig (Example 10 compared to Comparative Example 9 and Example 12 compared to Comparative Example 1 1). Compared to the mineral fillers v described in the prior art, however, a surprising synergistic effect is shown by the combination with nanofiller iv-1 -1 (cf., Example 1 1 compared to Comparative Example 10 and Example 13 compared to Comparative Example 13). This synergistic effect is more pronounced in the compounds with the higher amount of component ii-1, ie the compound in Example 11 with 18% ii-1 (based on the sum of i, ii) benefits disproportionately from the addition of nanofiller as the compound of Example 13 with only 10% ii-1 (based on the sum of i, ii).

* Diagonal crack propagation in the Elmendorf trial and thus falsified, because too high readings. Therefore, no comparison of the longitudinal forces is possible.

Example 15, containing 24% of component ii-1 (based on the sum of i, ii & iii) and another aliphatic-aromatic polyester type again demonstrates the surprising synergistic effect of the combination of mineral fillers v with nanofillers iv-3 in comparison to example 14 or comparative example 14.

Claims

claims 1 . Polyester blend containing i) from 5 to 90% by weight, based on the total weight of components i and ii, of at least one polyester based on aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds; ii) from 10 to 95% by weight, based on the total weight of components i and ii, of at least one homo- or copolyester selected from the group consisting of polylactides (PLA), polycaprolactones, polyhydroxyalkanoates and polyesters of aliphatic dicarboxylic acids and aliphatic diols; iii) 0.1 to 15 wt .-%, based on the total weight of components i and ii, a) of an epoxy group-containing copolymer based on styrene, acrylic acid ester and / or methacrylic acid ester, b) a bisphenol A epoxide or c) an epoxide group-containing natural oil, fatty acid ester or fatty acid amide; and iv) from 0.1 to 5% by weight, based on the sum of components i and ii, of iv-1) of one or more finely divided layered silicates whose surface has been modified with one or more quaternary ammonium salts or phosphonium salts and / or sulfonium salts , and / or iv-2) nanoparticulate silica produced by flame pyrolysis, whose surface is hydrophobically modified and which has a number-weighted diameter of the primary particles of 1 to 20 nm; v) 0 to 30 wt .-%, based on the sum of components i and ii, additives. A polyester mixture as claimed in claim 1, containing component iv-1 as component iv. A polyester mixture according to claim 2, containing as component iv natural montmorillonites and / or bentonites whose surface is modified with one or more quaternary ammonium salts. 4. polyester mixture according to claim 3, wherein the ammonium salts of component iv contain at least one long-chain (> d ₂ ) saturated or mono- or polyunsaturated alkyl radical. 5. polyester blend according to claim 4, wherein the ammonium salts are those of formula (VI),

where the symbols have the following meanings: R ¹ is identical or different and is a straight-chain, branched or cyclic, saturated or mono- or polyunsaturated hydrocarbon radical having 1 to 12 C atoms, which is unsubstituted or substituted by one or more OH groups; R ² is identical or different and is a straight-chain or branched, saturated or mono- or polyunsaturated hydrocarbon radical having 13 to 24 C atoms;  n is 0, 1, 2, 3 or 4, and  x is an anion. 6. polyester mixture according to any one of claims 1 to 5, wherein as component iv a nanodispersible layered silicate based on natural bentonites, modified with ammonium salt (VI-1), (CH ₃ ) ₂ N (HT) ₂ CI where HT means hydrogenated beef tallow,  or  a nanodispersible natural montmorillonite modified with ammonium salt (VI-2) (HIGH ₂ -CH ₂ ) ₃ N (T) CI (VI-2), where T is beef tallow,  is used. The biodegradable polyester blend of any one of claims 1 to 6, wherein component i is composed of: A) an acid component of a1) 30 to 99 mol% of at least one aliphatic or at least one cycloaliphatic dicarboxylic acid or its ester-forming derivatives or mixtures thereof a2) 1 to 70 mol% of at least one aromatic dicarboxylic acid or its ester-forming derivative or mixtures thereof and a3) 0 to 5 mol% of a sulfonate group-containing compound, wherein the molar percent of components a1) to a3) together give 100% and B) a diol component of at least one C ₂ to Ci ₂ alkanediol or one C ₅ - to Cio-cycloalkanediol or mixtures thereof and if desired, one or more components excluded beyond selects C) a component selected from c1) at least one dihydroxy compound of the formula I containing ether functions HO - [(CH ₂ ) _n -O] _m -H (I) in which n is 2, 3 or 4 and m is an integer from 2 to 250, c2) at least one hydroxycarboxylic acid of formula IIa or IIb

(IIa) (IIb) where p is an integer from 1 to 1500 and r is an integer from 1 to 4, and G is a radical selected from the group consisting of from phenylene, - (CH ₂ ) _q -, where q is an integer from 1 to 5, -C (R) H- and -C (R) HCH ₂ , where R is methyl or ethyl c3) at least one amino C ₂ - to C ₂ -alkanol or at least one amino-C ₅ -C Ci ₀ cycloalkanol, or mixtures thereof c4) at least one diamino-Cr to C ₈ alkane, c5) at least one 2,2'-bisoxazoline of the general formula III

where R ^{1 is} a single bond, a (CH ₂ ) _Z -alkylene group, where z = 2, 3 or 4, or a phenylene group c6) at least one aminocarboxylic acid selected from the group consisting of the natural amino acids, polyamides, obtainable by poly condensation of a dicarboxylic acid having 4 to 6 C atoms and a diamine having 4 to 10 C atoms, compounds of the formulas IV a and IVb

 (IVa) (IVb) in which s is an integer from 1 to 1500 and t is an integer from 1 to 4, and T is a radical selected from the group consisting of phenylene, - (CH ₂ ) _U -, wherein u is an integer from 1 to 12, -C (R ² ) H- and -C (R ² ) HCH ₂ , wherein R ^{2 is} methyl or ethyl, and polyoxazolines having the repeating unit V

in which R ^{3 is} hydrogen, C 1 -C ₆ -alkyl, C ₅ -C ₈ -cycloalkyl, unsubstituted or substituted by CrC ₄ alkyl groups up to three times substituted phenyl or tetra hydrofuryl, or mixtures of c1) to c6) and D) a component selected from d1) at least one compound having at least three groups capable of ester formation, d2) at least one isocyanate d3) at least one divinyl ether or mixtures of d1) to d3). 8. The polyester mixture according to any one of claims 1 to 7, wherein in component i: the aliphatic or cycloaliphatic dicarboxylic acid (component a1)) succinic acid, adipic acid or sebacic acid, their ester-forming derivatives or mixtures thereof;  the aromatic dicarboxylic acid (component a2)) terephthalic acid or ester-forming derivatives thereof, and  the diol component (component B) is 1,4-butanediol or 1,3-propanediol. 9. polyester mixture according to any one of claims 1 to 8, wherein component ii:  Polylactide or its stereocomplex, poly-3-hydroxybutyrate, poly-3-hydroxybutyrate-co-3-hydroxyvalerate, poly-3-hydroxybutyrate-co-3-hydroxyhexanoate, poly-3-hydroxybutyrate-co-4-hydroxybutyrate or a Mixture of the same is. 10. polyester mixture according to any one of claims 1 to 9, wherein component iii a) is an epoxy group-containing copolymer based on styrene, acrylic acid ester and / or methacrylic acid ester. 1 1. A polyester mixture according to any one of claims 1 to 9, comprising 15 to 80% by weight of component i and 85 to 20% by weight of component ii, in each case based on the total weight of components i to ii. 12. polyester blend according to any one of claims 1 to 1 1, wherein component i forms a continuous or co-continuous phase. The polyester blend of any one of claims 1 to 12, wherein between 10 and 30% of at least one inorganic filler is added as component v. The polyester blend of claim 13, wherein the mineral filler is calcium carbonate. The polyester blend of claim 13, wherein the mineral filler is a mixture of calcium carbonate and talc. 16. polyester mixture according to any one of claims 1 to 15, wherein the component ii consists of polylactide or its stereocomplex. 17. polyester mixture according to any one of claims 1 to 16, wherein the proportion of component ii based on the sum of components i and ii is between 10 and 30%. 18. polyester mixtures according to any one of claims 1 to 17, containing 75 to 85 wt .-% of component i;  15 to 25 wt .-% of component ii;  From 0.5% to 3% by weight of component iii;  0.4 to 2 wt .-% of component iv-1 and  15 to 30% by weight of talc and / or calcium carbonate as component v. 19. Polyester mixture according to one of claims 1 to 17, characterized in that it is biodegradable. 20. A process for the preparation of polyester mixtures according to claims 1 to 19, characterized in that the components i, ii and iii are mixed and reacted in one step. 21. Use of the polyester mixture according to claims 1 to 19 for the production of films, films, moldings or fibers. 22. Films, films, moldings or fibers, comprising a polyester mixture according to one of claims 1 to 19.